This invention relates to a process for producing patterned surfaces, and, more particularly, it relates to a process for electrically insulating and leveling patterned, preferably conducting surfaces.
It is often necessary, in micro-electronic circuits, to arrange a flat number of patterned surfaces, one above the other. This requires that the individual structures be well insulated from each other. Each insulating layer before the patterned conductors are applied should be relatively flat. At the same time sharp edges must be avoided on the lower layers of patterns.
It has been common practice to use a photoresistive material for this purpose in the past. This practice has the disadvantage, however, that the sides or edges of the conductors are not adequately covered. Good covering of the steps or transitions produced by the height of the conductive elements in the lower lying patterns is essential to providing the necessary insulating properties. A high degree of leveling of the patterned irregularities for a given layer thickness must be attained. (&gt;90% degree of smoothness).